Trolley conductor insulator



is interposed between the Patented Sept. 18, 1945 Raymond?. Hanna and `Willam B.

Pittsburgh, and Leland F. Brahmer,

Atkinson, Wilkinsburg, Pa., assignorsl to Westinghouse Electric- Corporatiom East Pitts of Pennsylvania burgh, Pa., a corporation Application February 27, 1943, SerialEc/PTLSW ('Cl. .TS1-639) 13 Claims.

Our invention relates, generally, to insulators for use in overhead trolley conductor systems and it has reference in particular to insulating run-'- ner members for overhead trolley conductor insulators. 1 Generally stated, 'it is an object of our invention to provide a trolley conductor insulator that is simple and inexpensive to manufacture and 'has improved operating characteristics.

More specically, -it is an object of our invention to provide for utilizing the heat resistant properties of inorganic materials to provide a durable insulating runner for a trolley conductor insulator.

It is also an .obje'ct of our invention to provide for utilizing the arc resisting properties of incr` ganic materials in runner members for trolley conductor insulators and protect the runner members against fracture from mechanical shock by supporting them intermediate the ends through interlocking relationship with, the insulating strain members of the insulators.

Another object of our invention is to provide for molding an insulati runner member for a trolley conductor insu ator from an 'aggregate of siliceous strength imparting materials with an inorganic cement.

Yet another .object of our invention is to provide a durable insulating runner member for trolley conductor systems wherein avfbrous inorganic insulating material is bonded by an inorganic cementitious bond.

Still another object of our invention is -tolpro-- vide for using the glazing action of siliceous materials when subject to the heat of an arc to reduce mechanical wear thereof and provide a durable insulating runner member for a trolley conductor device. y

Other objects will in part be obvious and will in part be explained hereinafter.

In accordance with our invention, a section insulator, insulated approach, insulating spacer, or the like, for a trolley conductor system is provided with a 'pair of spaced end members by which the insulator is connected to adjacent ends of a trolley conductor or to adjacent Aportions of a trolley conductor device. An insulating strain member connects the end members adjacent the lower edges thereof, while an insulating compression member upper edges of the end members.` An insulating runner member is positioned between the end members beneath Athe strain member to guide a current collector; The runner member is molded from an aggregate of asbestos fibers bonded by Portland cement and is provided with a runner portion along the lower edge and an elongated arcuate flange along the upper edge which partially surrounds and interlocks mechanically with 'the lower` portion of the strain member, so as to support the runner member substantially throughout its length against upward and lateral stresses. n

For a more .complete understanding of the nature and scope of our invention, reference may be had to the following detailed description, which may be read in connection with the accompanying drawing, in which: l A

Figure 1 is a side elevational view of a trolley conductor 'insulator embodying the principal features of the invention;

Fig. 2 is a cross sectional view taken along the line II-II of Fig. 1;

Fig. 3 is a side elevational view partly in section of a modified form of runner member; and

Fig. 4 is an end elevational view of the runner member shown in Fig. 3.

Referring to Fig. 1, the reference numeral I0 may denote generally a trolley conductor -insulator for use in trolley conductor systems. For the purposes of illustration an insulated approach is shown, for insulating a trolley conductor from a trolley device such as a frog or a crossing at an intersection. It will be understood that the invention is not limited to insulated approaches, but includes also section insulators for segregating adjacent sections of a trolley conductor, in.. sulated spacers for mechanically connecting and providing current collector paths between devices such as frogs or crossings at'an intersection, while insulating the positive and negative conductors from each other, and other types of trolley conductor insulators. n

The insulator l0 may comprise a pair of spaced end members l l and l2 having substantially upright body portions I3 and I4, with attaching means I6 and il, respectively, for securing the end members to adjacent portions of a trolley conductor system, such as, for example, a trolley 'conductor (not shown), and a trolley device such as a frog or a crossing (not shown). 'Ihe end Amembers maybe connected adjacent the lower ends by an insulatingstrain member I9 having connecting members 20 at the ends for effecting the connection. A compression member 2| may be interposed between the upper ends of the end v members, and may be provided with suitable adjusting means 22 for varying the length thereof to properly align the end members.

Referring to Figs. 1 and 2, it will be seen that the insulator l 0 may be provided with an insulating runner member 23 interposed between the end members and positioned beneath the strain member I3. The runner member 23 may comprise an elongated runner portion 24 along the lower edge for guiding a current collector, and projecting end portions 25 disposed to cooperate with substantially U-shaped support clips 21 for securing the runner member 23 in operating position.

In order to provide a runner member having as long a life as possible, it is necessary to take into account not only the normal mechanical wearing properties of the material of which the runner member is made, but also the arc resisting characteristics of the material and its resistance to mechanical shocks. In this respect, we have found that highly improved operating characteristics can be secured, particularly in the case where carbon or carbon insert shoes are used for collecting current, by using insulating runner members made from an inorganic insulating material. It may, for example, comprise a strength imparting inorganic material such as asbestos fiber, mica, mineral Wool, rock wool, or glass fibers, and an inorganic bond, such as Portland cement, Pozzolana cement, other silica base cements or mixtures thereof, or a ceramic bonding material, such as high silica glass, borosilicate glass, lead borate glass, enamel, zirconium oxide, kao1in,re clay, China clay and other red clays. Some of the ceramic materials, including the high strength glasses such as the high silica, borosilicate o1 other such glasses, and those which may comprise a more or less fused mass of stringy or fibrous glass, as well as some of the higher strength porcelains which have the necessary degree of resistance to mechanical shock, may be used without the addition of a separate strength imparting aggregate.

In the case of the cementitious bond, the. runner member may be either molded to the desired shape by any well known cold molding process and/or with heat and pressure by the application of steam or otherwise, or may be formed from suitable blanks of the material by machining, cutting, etc. The vitreous materials may either be hot molded, or formed cold and then iired according to the usual practice with the different vitreous materials. Y

In order to insure adequate mechanical strength against shock from blows either laterally or in the upward direction, the runner member 23 may be provided with a transversely arcuate reenforcing flange 28 along the upper edge of the runner portion. As shown in Figs. 1 and 2, the flange 28 may conform generally to the shape of the lower portion of the strain member I9. Openings 23 may be provided at spaced intervals in the flange 28 to drain the ,trough formed thereby. As may be seen best from Fig. 2 of the drawing, the flange may bear against the strain member I9 which may support the runner member 23 against upward stresses throughout substantially the entire length of the runner member. In addition, since the arcuate flange 28 partially surrounds the lower portion of the strain member I9, it may interlock mechanically therewith in the lateral direction so that the strain member re-enforces the runner member against lateral stresses also. The flange also reinforces the runner member in itself, against lateral stresses.

Referring to Figs. 3and 4, it will be seen that in a modied form the runner member 30 may comprise an elongated runner portion 3| having generally a V section rounded at the lower end and having end projections 32 of reduced section for positioning the runner member. The runner portion 3| may be provided with a substantially arcuate channel 33 along the upper edge thereof for receiving the lower portion of the strain member, so that the lips 34 thereof interlock mechanically with the lower portion of the strain member and re-enforce the runner member against lateral stresses.

In order to strengthen the projecting end portions 32 against fracture from mechanical shocks, suitable re-enforcing means, such as the rods or wires 35, may be used. With 'a view to securing the maximum reenforcement of the end projections, the re-enforcing wires may be positioned substantially centrally in the end projections and inclined downwardly towards the central portion of the body of the runner member adjacent the inner ends.

Inasmuch as many of the cementitious materials may be relatively porous, as are some of the strength imparting materials, it may be desirable, particularly when operating in extremely moist atmospheres, to prevent the absorption of too much moisture. With this purpose in view, the runner members may be impregnated with a suitable moisture inhibiting material. In this respect, tung oil or China-wood oil may be found satisfactory. While it is an organic material, only a very small quantity is necessary and it has a relatively high resistance to arcing. Other materials such as water glass, and borates such as lead borate may be used to Weatherproof the runner member. Dehydrated castor oil and various varnishes may also be used with success.

In Aview of the foregoing detailed description of our invention it will be apparent that we have provided an improved trolley conductor insulator which is simple and inexpensive to manufacture and has improved operating characteristics.

When used under conditions where they are ex- 'usual type. In some cases, runner members embodying our invention have outlasted several sets of the metal holding clips. Operating results with carbon shoes in particular show that both of these materials have inherently good resistance to mechanical wear and are exceedingly stable when exposed to arcing, under the initial stages of wear, they form a relatively smooth glaze which offers reduced friction to the passage of the current collectors and thus further reduces mechanical Wear of the current collectors and the runner members.

Since the embodiment of the invention disclosed in the above description may be changed and different embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all matter contained in theA above description or shown in the accompanying drawing shall be considered as illustrative and not in a limiting sense.

We claim as our invention:

1. For use with a trolley conductor insulator having a pair of spaced end members connected by insulating means, an abrasion and arc resisting insulating runner member of an unfused inorganic material comprising a siliceous aggregate extending between the end members beneath the insulating means.

Y 2. A section insulator comprising, a pair of spaced metal end members, insulating means including a strain member of an organic insulating material and having a rounded lower edge mechanically connecting the end members, and an insulating runner member positioned beneath the insulating means and having an arcuate groove along the upper edge for receiving the lower edge of the insulating means comprising an aggregate of strength imparting inorganic insulating material bonded by a cementitious inorganic binder.

3. An insulator comprising, a pair of spaced apart end members for connection to adjoining portions in a trolley system, a pair of vertically spaced insulating members mechanically connecting the end members, and an insulating runner member comprising lan aggregate of asbestos fibers bonded by an inorganic cement positioned beneath the lower insulating member having a substantially solid runner portion along the lower edge and a transversely extending arcuate reenforcing flange along the upper edge engaging and partially surrounding a portion of the lower insulating member so as to interlock mechanically therewith and prevent lateral distortion of the inner member.

4. The combination in a trolley conductor insulator, of a pair of spaced end members having means for attachment to adjacent portions of an roverhead trolley system, insulating means connecting the end members in spaced insulated relation, and an insulating runner member detachably positioned beneath the insulating means comprising a frangible body of siliceous materlals bonded by Portland cement having a lower edge for guiding a current collector and a transversely arcuate upper surface engaging and partially surrounding the lower portion of the insulating means so as to prevent displacement of the runner member relative to the insulating means and reinforce the runner member.

5. An insulating rimner member for use with a trolley conductor insulator having spaced metallic end members connected by insulating means comprising, an elongated body member of a strength imparting siliceous aggregate bonded by a cold setting inorganic cement having a substantially solid runner portion along the lower edge and a transversely arcuate ange along the upper edge dening a groove to receive the lower portion of the insulating means.

6. An insulating runner member comprising a body of insulating material having a substantially solid runner portion along the lower edge for guiding a current collector and a transversely arcuate flange projection along the upper edge dening an arcuate groove and having openings therethrough extending downwardly and out- Wardly from the bottom of the groove to provide drains for the groove.

7. An insulating runner member for use with an insulating strain member in trolley conductor devices used with carbonaceous current collectors comprising, an elongated runner member comprising a substantially solid body portion of a relatively long fiber asbestos bonded by Portland cement having a runner surface alongl the lower edge for guiding a current collector and a transversely arcuate upper surface for receiving the lower portion of the strain member to reenforce the runner member against mechanical shock.

8. An insulating runner member for an insulated spacer comprising, an elongated ceramic body member having a collector guiding lower edge and a transversely arcuate flange along the upper edge.

9. The combination in an insulating runner member for a trolley device, of an elongated body member of a siliceous aggregate bonded by an inorganic bond having a substantially solid runner portion with a relatively shallow groove on the upper side.

10. An insulating runner member for use with section insulators in trolley systems comprising an elongated runner member of insulating material having a runner surface along the lower edge for guiding a current collector, and having a longitudinal groove along the upper edge provided with spaced openings through the sidewalls at the bottom of the groove.

11. An insulating runner member for trolley conductor devices comprising, an elongated body member molded from an aggregate of mica bonded by a vitreous cement.

12. An insulating runner member for an insulated spacer in a trolley conductor system comprising, an elongated body member having a runner surface along the lower surface and an arcuate groove along the upper surface, said body member comprising an aggregate of siliceous materials bonded by an inorganic cement and impregnated with a weather resistant medium.

13. An insulating runner member for a trolley device comprising, an elongated body runner portion having a laterally projecting flange along the upper side and projecting end portions with internal re-enforcing means extending into the body runner portion and projecting end portions, said body runner portion comprising an aggregate of a relatively flexible strength imparting siliceous material bonded by an inorganic cement.

RAYMOND P. HANNA. WILLIAM B. ATKINSON. LELAND F. BRAHMER. 

